The present invention relates in general to personal computers which include slots for receiving integrated circuit (IC) cards compatible with Personal Computer Memory Card International Association (PCMCIA) standards, i.e. PCMCIA slots, and, more particularly, to a method and apparatus for expanding a PCMCIA slot of a personal computer to provide multiple access points to the computer via a PCMCIA slot by allocating the address space available for a PCMCIA compatible IC card to define one or more operable PCMCIA slots, one or more serial and parallel ports, other peripheral or auxiliary devices and various other access and control features for the computer and/or IC cards.
Portable computers and other electronic devices are being reduced in size as advances in technology reduce the size of components used to manufacture these devices. Along with this size reduction, compact slots have been provided in the devices for receiving IC cards. While these slots provide access to a large variety of IC cards which perform a corresponding variety of operations useful for the receiving devices, unfortunately the number of access points more conventionally associated with personal computers, such as serial and parallel ports and expansion slots for receiving other peripheral or auxiliary devices, have typically been eliminated.
In an effort to standardize the IC card formats, the PCMCIA has promulgated various standards governing the physical dimensions and interface configuration of IC cards. These standards are set forth in detail in the PC Card Standard, Release 2.0, issued by the PCMCIA, dated September 1991, the disclosure of which is hereby incorporated by reference.
In brief, the PCMCIA standards set forth IC card physical dimensions, electrical interface requirements between IC cards and the devices utilizing the IC cards, and a data format for the interchange of information between IC cards and devices utilizing IC cards. Each PCMCIA IC card is connected to a compatible device through a 68-pin, two piece pin and socket connector with the IC card including the pin portion of the connector. The data format provides for 64 megabytes of address space for use by each IC card.
Computer manufacturers have wholeheartedly endorsed the PCMCIA standards and have included at least one slot for a PCMCIA card in virtually all laptop, subnotebook and notebook computers. In response to the increasing popularity of the PCMCIA standards, numerous PCMCIA compatible devices, such as hard drives, modems, local area network (LAN) adapters and wireless communications systems, have been developed. For example, one communications card which serves the functions of a modem conforming to the PCMCIA standards is manufactured by Intel under the ExCA.RTM. trademark. Other similar PCMCIA compatible communications cards are used in local area networks (LAN's).
Another example of a PCMCIA compatible communications card is disclosed in U.S. Pat. No. 5,183,404 issued to Aldous et al. Aldous et al. disclose a PCMCIA compatible communications card for interconnecting a PCMCIA slot of a computer to a conventional RJ-11 plug for interconnecting telephone lines.
While the PCMCIA standards have greatly assisted compatibility between IC cards and using devices, unfortunately the number and types of peripheral or auxiliary devices which may be concurrently connected to using devices is limited since the more conventional access points, such as serial and parallel ports, are typically not provided.
It is thus apparent that a need exists in the art for providing additional access points to laptop, subnotebook and notebook computers, typically limited to one or more PCMCIA slots, without detracting from the compact nature of these computers which has made them very popular to computer users. Ideally, the additional access points would be provided through a PCMCIA slot such that not only new compact computers but also existing compact computers and other devices including a PCMCIA slot would be able to take advantage of the expanded access points.